EP0173131B1 - Procédé pour la séparation de composés nitroaromatiques de l'acide nitrique utilisé - Google Patents

Procédé pour la séparation de composés nitroaromatiques de l'acide nitrique utilisé Download PDF

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Publication number
EP0173131B1
EP0173131B1 EP85109889A EP85109889A EP0173131B1 EP 0173131 B1 EP0173131 B1 EP 0173131B1 EP 85109889 A EP85109889 A EP 85109889A EP 85109889 A EP85109889 A EP 85109889A EP 0173131 B1 EP0173131 B1 EP 0173131B1
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EP
European Patent Office
Prior art keywords
nitric acid
nitration
medium
acid
nitroaromatic
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP85109889A
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German (de)
English (en)
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EP0173131A1 (fr
Inventor
Richard Van Court Carr
David Samuel Ross
Bernard Allen Toseland
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Air Products and Chemicals Inc
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Air Products and Chemicals Inc
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Publication of EP0173131A1 publication Critical patent/EP0173131A1/fr
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Classifications

    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C201/00—Preparation of esters of nitric or nitrous acid or of compounds containing nitro or nitroso groups bound to a carbon skeleton
    • C07C201/06—Preparation of nitro compounds
    • C07C201/16—Separation; Purification; Stabilisation; Use of additives
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B21/00—Nitrogen; Compounds thereof
    • C01B21/20—Nitrogen oxides; Oxyacids of nitrogen; Salts thereof
    • C01B21/36—Nitrogen dioxide (NO2, N2O4)

Definitions

  • This invention relates to a process for efficient separation of nitroaromatic compositions from a reaction product comprising nitric acid, unreacted aromatic compound and nitroaromatic.
  • Nitroaromatic compositions have been widely used as intermediates in the chemical industry, and are well suited for producing a variety of industrial chemicals such as aromatic amines for use as chain extenders in polyurethane manufacture or in preparation of aromatic isocyanates for urethane synthesis.
  • Examples of widely used nitroaromatic compositions include mono and dinitrobenzene, mono and dinitrotoluene and mono and dinitroxylene.
  • the '466 patent differs from the other two patents in that nitrogen dioxide is injected into the reaction medium of aromatic compound and sulfuric acid as opposed to nitric acid injection into the reaction medium.
  • nitric acid alone as the nitrating agent in the manufacture of both mono and dinitroaromatic compounds.
  • a more concentrated nitric acid is utilized, e.g. fuming nitric acid as the nitrating agent than when the mononit- roaromatic is prepared.
  • Representative patents which disclose various nitration processes using nitric acid alone include U.S. 2,362,743; 2,739,174; 3,780,116; and 4,112,005.
  • nitric acid as the nitrating medium, they differ in the selectivity to either mono or dinitrated product produced or in the use of different mole ratios of nitric acid to aromatic compounds or in the use of different process techniques to effect nitration.
  • nitration procedure for producing nitrated aromatic composition resides in the use of nitrogen oxides alone or in combination with sulfuric acid or oxygen as the nitrating medium.
  • Various nitrogen oxides such as N 2 0 5 , N0 2 and N 1 0 4 have been utilized as the nitrating agent.
  • the 4,028,425 patent provides for the introduction of nitrogen dioxide and oxygen into an aromatic hydrocarbon with the coproduction of the dinitroaromatic compound and concentrated nitric acid as a product.
  • each of the processes described above requires separation of the nitroaromatic compound from the unreacted aromatic compound and spent nitric acid.
  • the spent nitric acid contains a substantial amount of water which must be removed in order to recover the spent nitric acid and recovering the unreacted aromatic hydrocarbon.
  • Recovery of residual nitric acid in the reaction product is a major commercial objective in preparing dinitroaromatic compounds where the amount of residual acid is substantial. In mononitration reactions the amount of residual nitric acid may be less than in dinitration reactions, and recovery may not be as important as is the separation of the nitroaromatic and unreacted aromatic compounds from the spent acid.
  • U.S. 4,257,986 discloses the separation of the organic phase from the spent acid phase in a mixed acid nitration process and then introducing unreacted aromatic compound into the spent acid phase under nitrating conditions to generate mononit- roaromatic compound. The reaction product then is allowed to separate into various phases and the aqueous phase removed from the organic phase containing the nitroaromatic compound and unreacted aromatic.
  • U.S. 2,849,497 discloses the separation of the organic layer from the aqueous layer which consists primarily of nitric acid; sulfuric acid, nitroaromatic compound and water.
  • the '497 process involves the introduction of additional unreacted aromatic compounds into the spent acid phase to denitrate the spent acid.
  • the advantage of the process is that the nitric acid, which is dissolved in the crude nitroaromatic, is advantageously recovered for the preparation of additional product rather than being washed out first.
  • One of the more conventional techniques for removing spent nitric acid from the reaction mixture, with either the mixed acid process, the nitric acid process or a nitrogen oxides process, is the neutralization of the spent acid by reaction with alkali and the products thus separated.
  • U.S. 1,325,168 discloses the neutralization of the nitric acid with a base, such as lime, ammonia, or the like, and then removing the nitrobenzene in a pure state by distillation.
  • Solvent extraction using carbon tetrachloride is also suggested as being an alternative to the neutralization technique.
  • U.S. 2,736,742 discloses the uses of a mixture or solution of ammonia and organic bases with ammonium nitrate to effect removal of nitric acid.
  • U.S. 4,261,908 discloses the separation of dinitroaromatics from nitric acid by distillation.
  • nitric acid from nitroaromatic compositions produced in aromatic dinitration processes has been a continuing problem.
  • the problem is more severe in dinitration reactions than in mononitration reactions and is more severe in those processes using nitric acid alone as the nitrating medium.
  • the spent nitric acid present in a dinitration reaction has a much higher concentration than normally used when a mixed acid process is used.
  • removal of the nitric acid typically cannot be effected by the introduction of fresh aromatic because such conditions are not suited for nitration.
  • modest nitration can be achieved by the mixed process to the mononitro product.
  • the processes which rely on neutralization techniques in an effort to recover nitrated aromatic compounds from the nitration wash liquors as represented in the 4,224,249 patent disclose problems with respect to the sewering and problems associated with biological treatment.
  • This invention pertains to a process for extracting nitroaromatic compositions from a nitric acid medium generated in the nitration of aromatic compounds.
  • the reaction product typically contains nitroaromatic compound, nitric acid, and water.
  • Optionally unreacted aromatic and miscellaneous byproducts may be present in the nitration product medium.
  • the extraction process is achieved by introducing nitric oxide (NO) into the nitric acid medium under conditions sufficient to react with the nitric acid present therein to generate nitrogen dioxide (N0 2 ) and water.
  • the gaseous nitrogen dioxide then can be removed from the nitration medium and subsequently used to regenerate or form nitric acid.
  • the process of this invention can be utilized for the recovery of nitric acid from the nitration of aromatic compounds using nitric acid alone, the mixed acid technique or a mixture of nitrogen oxides wherein the reaction product contains nitroaromatic dissolved in nitric acid and water.
  • Typical aromatics formed by these nitration processes include nitrobenzene, nitrotoluene and nitroxylene.
  • the recovery of nitric acid from the nitration medium is achieved by introducing nitric oxide into the reaction medium under conditions sufficient for the nitric oxide to react with the nitric acid to form gaseous nitrogen dioxide and water. Sufficient nitric oxide must be added to the nitration medium in order to react with the residual nitric acid in the medium to generate the product nitrogen dioxide and water. As the concentration of nitric acid in the spent acid phase is reduced, nitroaromatic compounds will be forced from the spent acid or aqueous phase and into the organic phase. The nitrogen dioxide generated by the reaction between nitric oxide and nitric acid is removed as a gas and can be further oxidized in a separate unit to form nitric acid for further reaction. The water which is formed in the reaction between nitric acid and nitric oxide is a byproduct and can simply be disposed of through a conventional waste treatment system.
  • Conditions suited for the reaction of nitric oxide with nitric acid to gaseous nitrogen oxides are typically from about 0 to 90°C. Temperatures lower than about 70°C achieve the recovery of nitric acid from the nitration medium while simultaneously effecting extraction of the nitroaromatic from the nitration medium.
  • nitric oxide In order to recover substantially all of the nitric acid in the spent acid phase, sufficient nitric oxide must be introduced into the unit to achieve sufficient reduction of the nitric acid to generate an insoluble organic fraction. Normally at least one mole of nitric oxide is required to react with two moles of nitric acid in order to effect full decomposition of the nitric acid. For purposes of practicing the invention, it is preferred that a slight excess, e.g. 10% greater than stoichiometric amounts are used in order to insure that substantially all of the nitric acid is recovered. The excess nitric oxide can then be oxidized to nitrogen dioxide for subsequent conversion to nitric acid. Therefore, there is little, if any, loss of the nitric acid or nitric oxide in the extraction of the nitroaromatic from the spent acid phase and effect recovery of the nitric acid.
  • a slight excess e.g. 10% greater than stoichiometric amounts
  • the above experiment demonstrates NO decompostion as an extraction technique for separating.
  • the material trapped overhead weighed 11.37 g which represents 71.1% of the starting , material on a weight basis.
  • the trap was raised to room temperature and N 2 at 1 sccm was passed through the trap. After a period of venting condensed gases, which vaporized at the low elevated temperature, 0.648 g of liquid was left. This liquid was assumed to be any entrained water or nitric acid. this represents 4.1% of the starting material.
  • a gc analysis showed the trapped material to be free of any 2,4-dinitrotoluene.
  • the material remaining in the reactor weighed 5.92 g. Upon separation, 1.145 g ofthe starting 2,4-dinitrotoluene were recovered, representing 98.11% recovery. The material other than the 2,4-dinitrotoluene was titrimetrically analyzed to be 47.33% HN0 3 .
  • This experiment demonstrates the passage of NO through a solution of 2,4-dinitrotoluene in aqueous nitric acid to decompose a substantial portion of the starting nitric acid, with a high efficiency of NO consumption. In this case, 83% of the nitric acid was recovered with an NO efficiency of 77%.
  • This example demonstrates decomposition of a simulated nitric acid phase.
  • the NO passed was 95.4 mmole.

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Claims (8)

1. Procédé pour la séparation d'un composé nitro-aromatique, en solution dans un milieu de nitration, contenant de l'acide nitrique, de l'eau et le composé nitro-aromatique, tandis qu'est formé en même temps un oxyde d'azote, apte à être converti en acide nitrique, comprenant la mise en contact du milieu de nitration avec une quantité suffisante d'oxyde nitrique, sous des conditions favorables à la réaction avec l'acide nitrique mentionné, pour former du bioxyde d'azote et de l'eau, l'oxyde nitrique étant présent en une quantité suffisante pour réagir avec l'acide nitrique dans le milieu de nitration.
2. Procédé selon la revendication 1, dans lequel le composé nitro-aromatique cité est le nitrotoluène.
3. Procédé selon la revendication 2, dans lequel le nitrotoluène cité est le dinitroluène.
4. Procédé selon la revendication 1, dans lequel le composé nitro-aromatique cité est le nitrobenzène.
5. Procédé selon la revendication 4, dans lequel le nitrobenzène cité est le dinitroben- zène.
6. Procédé selon la revendication 1, dans lequel l'oxyde nitrique est ajouté en une quantité de 1 à 1,1 mole pour 2 moles d'acide nitrique.
7. Procédé selon la revendication 6, dans lequel l'oxyde nitrique est ajouté au milieu de nitration sous des conditions telles que la température de réaction se situé dans l'intervalle d'environ 0 à 90°C.
8. Procédé selon une des revendications précédentes pour la séparation d'un composé de dinitroaromatique, en solution dans un milieu de nitration, contenant de l'eau, de l'acide nitrique et le composé dinitro-aromatique, comprenant,
a) la mise en contact du milieu de nitration avec de l'oxyde nitrique sous des conditions favorables à la réaction avec l'acide nitrique, pour former du bioxyde d'azote gazeux et de l'eau, créant ainsi un milieu concentré du composé dinitroaromatique;
b) le refroidissement du milieu mentionné pour solidifier ce composé dinitro-aromatique, et
c) la séparation de ce composé dinitro-aromatique solidifié à partir du milieu de nitration refroidi.
EP85109889A 1984-08-07 1985-08-06 Procédé pour la séparation de composés nitroaromatiques de l'acide nitrique utilisé Expired EP0173131B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US638436 1984-08-07
US06/638,436 US4642396A (en) 1984-08-07 1984-08-07 Process for separating nitroaromatic compounds from spent nitric acid

Publications (2)

Publication Number Publication Date
EP0173131A1 EP0173131A1 (fr) 1986-03-05
EP0173131B1 true EP0173131B1 (fr) 1989-04-19

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US (1) US4642396A (fr)
EP (1) EP0173131B1 (fr)
DE (1) DE3569522D1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103936591A (zh) * 2014-04-14 2014-07-23 中国五环工程有限公司 亚硝酸甲酯的再生方法

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4754083A (en) * 1986-04-24 1988-06-28 Amoco Corporation Para selectivity in catalyzed disubstitutions of monosubstituted benzenes containing meta-directing substituents
US5006325A (en) * 1989-08-28 1991-04-09 Air Products And Chemical, Inc. Process for the recovery of nitric acid
DE4216416C1 (fr) * 1992-05-18 1993-05-13 Bayer Ag, 5090 Leverkusen, De
US6506948B1 (en) 2002-02-07 2003-01-14 Air Products And Chemicals, Inc. Toluene extraction of dinitrotoluene wash water
DE10329304A1 (de) * 2003-06-30 2005-02-03 Bayer Materialscience Ag Verfahren zur Aufarbeitung des bei der Herstellung von Dinitrotoluol anfallenden Abwassers
DE102006033722A1 (de) * 2006-07-21 2008-01-24 Bayer Materialscience Ag Verfahren zur Herstellung von Dinitrotoluol
ES2444276T3 (es) * 2009-12-16 2014-02-24 Basf Se Procedimiento para el tratamiento de gases de escape que contienen NOx procedentes de aguas residuales de instalaciones de nitración

Family Cites Families (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2656395A (en) * 1953-10-20 Preparation of nitroolefins
US1325168A (en) * 1919-12-16 Lucien jean joseph perruche
US2362743A (en) * 1943-02-10 1944-11-14 Hercules Powder Co Ltd Manufacture of dinitrotoluene
US2739174A (en) * 1951-09-08 1956-03-20 Eastman Kodak Co Nitrating aromatic hydrocarbons with only nitric acid
US2736742A (en) * 1954-07-08 1956-02-28 Nitroglycerin Ab Method of processing acid nitrated organic products
US2867669A (en) * 1954-08-19 1959-01-06 Gen Electric Method of forming mononitro hydrocarbons
US2849497A (en) * 1956-10-10 1958-08-26 Du Pont Preparation of nitrobenzene
US2883432A (en) * 1957-04-16 1959-04-21 Du Pont Process for the production of saturated aliphatic nitro compounds
DE1418624C3 (de) * 1960-12-22 1973-01-04 Ab Chematur, Stockholm Verfahren zur kontinuierlichen Herstellung von Dinitrotoluol, Trinitrotoluol und deren Gemischen
US3185738A (en) * 1962-11-01 1965-05-25 Du Pont Preparation of meta-dinitrobenzene by a two-stage nitration process
US3780116A (en) * 1972-06-15 1973-12-18 Zaverchand & Co Method for nitration of aromatic hydrocarbon compounds
IN141261B (fr) * 1973-06-29 1977-02-05 Meissner J
DE2622313C3 (de) * 1976-05-19 1980-09-25 Bayer Ag, 5090 Leverkusen Verfahren zur kontinuierlichen Herstellung von Mononitroaromaten
US4028425A (en) * 1976-06-01 1977-06-07 The United States Of America As Represented By The Secretary Of The Army Continuous process for concurrent production of dinitrotoluene and high-strength nitric acid
DE2704680A1 (de) * 1977-02-04 1978-08-10 Bayer Ag Verfahren zur gewinnung von aromatischen dinitroverbindungen
US4123466A (en) * 1977-12-12 1978-10-31 The Upjohn Company Process for nitrating aromatic hydrocarbons
US4257986A (en) * 1979-02-02 1981-03-24 Air Products And Chemicals, Inc. Process for refining aqueous acid mixtures utilized in nitration of aromatics
US4517394A (en) * 1983-07-05 1985-05-14 W. R. Grace & Co. Preparation of nitro compounds by vapor phase nitration of carboxylic acids
US4496782A (en) * 1983-07-08 1985-01-29 Air Products And Chemicals, Inc. Nitric acid recovery by the adiabatic nitration of nitroaromatics with fortified spent acid

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103936591A (zh) * 2014-04-14 2014-07-23 中国五环工程有限公司 亚硝酸甲酯的再生方法
CN103936591B (zh) * 2014-04-14 2015-09-16 中国五环工程有限公司 亚硝酸甲酯的再生方法

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EP0173131A1 (fr) 1986-03-05
US4642396A (en) 1987-02-10
DE3569522D1 (en) 1989-05-24

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